Distributed transaction processing networks, accepting transactions from widely dispersed POS (point of service) terminals, are known in the prior art. Typically such networks are provided with a distributed set of local line concentrators and a centralized means of monitoring and control; typically the centralized monitoring and control means initiate testing at far-flung points in the network and initiate actions to work around any detected faults.
As such networks become larger in geographical scope (on the order of entire continents), the centralized monitoring and control means are able to focus their attention on each particular point in the network less and less frequently (in practice, in the present embodiment, on the order of once every ten minutes); thus, a failure in a POS terminal, a line concentrator, or the path interconnecting them might go undetected by the central control means and therefore uncorrected for a period of time that is unacceptably long in a retail POS setting.